Economic-Financial Assessment of Seawater Desalination Plants in Northern Chile to Reduce Hydric Scarcity and a Proposal for the Environmental and Sustainable Use of Brine Waste by Cultivating the Microalga Dunaliella salina to Produce β-Carotene

Climate change and global warming generate serious consequences and disturbances by drastically modifying historical temperature and precipitation patterns. Water scarcity is one of the most revealing phenomena of these instabilities. This transdisciplinary bibliometric and economic-financial research focuses on analyzing two aspects: first, the feasibility of implementing seawater desalination plants as a solution to water scarcity in northern Chile. Investment and amortization costs of the desalination plants were determined (NPV-IRR-IRP). NPV showed a positive value indicating a recovery of the initial investment and a surplus over profitability. The IRR was higher than the discount rate calculated for NPV, which showed that the investment project was accepted. The IRP indicated that the initial investment of the plant would be recovered in 3.7 years. Second, an innovative and environmentally sustainable solution to the brine (NaCl) waste generated by desalination plants is proposed through the cultivation of Dunaliella salina microalgae tolerant to high brine concentrations to produce beta-carotene. The analyzed desalination plants and the sustainable use of brine residues offer interesting economic perspectives to a 10-year projection establishing a surplus over profitability. The SWOT analysis estimates an excellent production of beta-carotene through the microalgae and alternatives to the problem of sea pollution by concentrated brine waste.